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@mikejacobs.bsky.social Oct 9, 2026, 11:09 AM

Here's a #yohaku to take you into the weekend. Fill in cells with 16 different factors of 990 to get totals shown in each row/column AND shaded cells contain prime numbers. #mathsky #iTeachMath

Use 16 different factors of 990 in a 4 by 4 grid. The numbers in the top row add to 118. The numbers in the second row add to 170. The numbers in the third row add to 47. The numbers in the bottom row add to 31. The numbers in the left column add to 180. The numbers in the second column add to 40. The numbers in the third column add to 28. The numbers in the right column add to 118. The central four cells contain prime numbers.

@mikejacobs.bsky.social Oct 8, 2026, 11:14 AM

Try this shady #yohaku. Fill in cells with 9 different integers to get products shown in each row/column AND sum of 4 shaded cells is -2. #mathsky #iTeachMath

Use 9 different integers in a 3 by 3 grid. The numbers in the top row multiply to -42. The numbers in the middle row multiply to 55. The numbers in the bottom row multiply to 54. The numbers in the left column multiply to -66. The numbers in the middle column multiply to 63. The numbers in the right column multiply to 30. The sum of the integers in the 2 by 2 square at the top left of the grid is -2.

@mikejacobs.bsky.social Oct 7, 2026, 10:58 AM

Start your day with this #yohaku. Fill in cells with 9 different factors of 448 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 448 in a 3 by 3 grid. The numbers in the top row add to 58. The numbers in the middle row add to 233. The numbers in the bottom row add to 38. The numbers in the left column add to 254. The numbers in the middle column add to 28. The numbers in the right column add to 47.

@mikejacobs.bsky.social Oct 6, 2026, 11:11 AM

"Start your day with this #yohaku. Fill in cells with 9 different whole numbers to get products shown in each row/column. More free puzzles and books/ebooks for all ages can be found at yohaku.ca

Use 9 different whole numbers in a 3 by 3 grid. The numbers in the top row multiply to 78. The numbers in the middle row multiply to 84. The numbers in the bottom row multiply to 160. The numbers in the left column multiply to 52. The numbers in the middle column multiply to 112. The numbers in the right column multiply to 180.

@mikejacobs.bsky.social Oct 5, 2026, 11:18 AM

Start your week with this #yohaku. Fill in cells with 9 different factors of 444 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 444 in a 3 by 3 grid. The numbers in the top row add to 151. The numbers in the middle row add to 80. The numbers in the bottom row add to 19. The numbers in the left column add to 191. The numbers in the middle column add to 42. The numbers in the right column add to 17.

@mikejacobs.bsky.social Oct 2, 2026, 12:16 PM

Here's a #yohaku to take you into the weekend. Fill in cells with 16 different factors of 630 to get totals shown in each row/column AND shaded cells contain prime numbers. #mathsky #iTeachMath

Use 16 different factors of 630 in a 4 by 4 grid. The numbers in the top row add to 101. The numbers in the second row add to 35. The numbers in the third row add to 53. The numbers in the bottom row add to 74. The numbers in the left column add to 30. The numbers in the second column add to 63. The numbers in the third column add to 97. The numbers in the right column add to 73. The central four cells contain prime numbers.

@mikejacobs.bsky.social Oct 1, 2026, 10:55 AM

Try this shady #yohaku. Fill in cells with 9 different integers to get products shown in each row/column AND sum of 4 shaded cells is -3. #mathsky #iTeachMath

Use 9 different integers in a 3 by 3 grid. The numbers in the top row multiply to -78. The numbers in the middle row multiply to 35. The numbers in the bottom row multiply to -330. The numbers in the left column multiply to -20. The numbers in the middle column multiply to -231. The numbers in the right column multiply to 195. The sum of the integers in the 2 by 2 square at the top left of the grid is -3.

@mikejacobs.bsky.social Sep 30, 2026, 10:55 AM

Start your day with this #yohaku. Fill in cells with 9 different factors of 930 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 930 in a 3 by 3 grid. The numbers in the top row add to 36. The numbers in the middle row add to 96. The numbers in the bottom row add to 202. The numbers in the left column add to 98. The numbers in the middle column add to 218. The numbers in the right column add to 18.

@mikejacobs.bsky.social Sep 29, 2026, 11:10 AM

"Start your day with this #yohaku. Fill in cells with 9 different whole numbers to get products shown in each row/column. More free puzzles and books/ebooks for all ages can be found at yohaku.ca

Use 9 different whole numbers in a 3 by 3 grid. The numbers in the top row multiply to 64. The numbers in the middle row multiply to 195. The numbers in the bottom row multiply to 42. The numbers in the left column multiply to 42. The numbers in the middle column multiply to 104. The numbers in the right column multiply to 120.

@mikejacobs.bsky.social Sep 28, 2026, 11:13 AM

Start your week with this #yohaku. Fill in cells with 9 different factors of 580 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 580 in a 3 by 3 grid. The numbers in the top row add to 69. The numbers in the middle row add to 150. The numbers in the bottom row add to 151. The numbers in the left column add to 175. The numbers in the middle column add to 19. The numbers in the right column add to 176.

@mikejacobs.bsky.social Sep 25, 2026, 11:19 AM

Here's a #yohaku to take you into the weekend. Fill in cells with 16 different factors of 660 to get totals shown in each row/column AND shaded cells contain triangle numbers. #mathsky #iTeachMath

Use 16 different factors of 660 in a 4 by 4 grid. The numbers in the top row add to 13. The numbers in the second row add to 160. The numbers in the third row add to 153. The numbers in the bottom row add to 47. The numbers in the left column add to 77. The numbers in the second column add to 28. The numbers in the third column add to 148. The numbers in the right column add to 120. The central four cells contain triangle numbers.

@mikejacobs.bsky.social Sep 24, 2026, 10:59 AM

Try this shady #yohaku. Fill in cells with 9 different integers to get products shown in each row/column AND sum of 4 shaded cells is -8. #mathsky #iTeachMath

Use 9 different integers in a 3 by 3 grid. The numbers in the top row multiply to -125. The numbers in the middle row multiply to -27. The numbers in the bottom row multiply to -112. The numbers in the left column multiply to 90. The numbers in the middle column multiply to 525. The numbers in the right column multiply to -8. The sum of the integers in the 2 by 2 square at the top left of the grid is -8.

@mikejacobs.bsky.social Sep 23, 2026, 11:13 AM

Start your day with this #yohaku. Fill in cells with 9 different factors of 510 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 510 in a 3 by 3 grid. The numbers in the top row add to 120. The numbers in the middle row add to 66. The numbers in the bottom row add to 24. The numbers in the left column add to 46. The numbers in the middle column add to 25. The numbers in the right column add to 139.

@mikejacobs.bsky.social Sep 22, 2026, 10:58 AM

"Start your day with this #yohaku. Fill in cells with 9 different whole numbers to get products shown in each row/column. More free puzzles and books/ebooks for all ages can be found at yohaku.ca

Use 9 different whole numbers in a 3 by 3 grid. The numbers in the top row multiply to 72. The numbers in the middle row multiply to 39. The numbers in the bottom row multiply to 385. The numbers in the left column multiply to 63. The numbers in the middle column multiply to 66. The numbers in the right column multiply to 260.

@mikejacobs.bsky.social Sep 21, 2026, 11:11 AM

Start your week with this #yohaku. Fill in cells with 9 different factors of 460 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 460 in a 3 by 3 grid. The numbers in the top row add to 29. The numbers in the middle row add to 122. The numbers in the bottom row add to 52. The numbers in the left column add to 71. The numbers in the middle column add to 35. The numbers in the right column add to 97.

@mikejacobs.bsky.social Sep 18, 2026, 11:20 AM

Here's a #yohaku to take you into the weekend. Fill in cells with 16 different factors of 960 to get totals shown in each row/column AND shaded cells contain triangle numbers. #mathsky #iTeachMath

Use 16 different factors of 960 in a 4 by 4 grid. The numbers in the top row add to 11. The numbers in the second row add to 60. The numbers in the third row add to 239. The numbers in the bottom row add to 70. The numbers in the left column add to 26. The numbers in the second column add to 155. The numbers in the third column add to 38. The numbers in the right column add to 161. The central four cells contain triangle numbers.

@mikejacobs.bsky.social Sep 17, 2026, 11:13 AM

Try this shady #yohaku. Fill in cells with 9 different integers to get products shown in each row/column AND sum of 4 shaded cells is -2. #mathsky #iTeachMath

Use 9 different integers in a 3 by 3 grid. The numbers in the top row multiply to -102. The numbers in the middle row multiply to -70. The numbers in the bottom row multiply to 143. The numbers in the left column multiply to -273. The numbers in the middle column multiply to 85. The numbers in the right column multiply to -44. The sum of the integers in the 2 by 2 square at the top left of the grid is -2.

@mikejacobs.bsky.social Sep 16, 2026, 11:13 AM

Start your day with this #yohaku. Fill in cells with 9 different factors of 520 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 520 in a 3 by 3 grid. The numbers in the top row add to 79. The numbers in the middle row add to 86. The numbers in the bottom row add to 116. The numbers in the left column add to 182. The numbers in the middle column add to 49. The numbers in the right column add to 50.

@mikejacobs.bsky.social Sep 15, 2026, 11:08 AM

"Start your day with this #yohaku. Fill in cells with 9 different whole numbers to get products shown in each row/column. More free puzzles and books/ebooks for all ages can be found at yohaku.ca

Use 9 different whole numbers in a 3 by 3 grid. The numbers in the top row multiply to 54. The numbers in the middle row multiply to 70. The numbers in the bottom row multiply to 156. The numbers in the left column multiply to 168. The numbers in the middle column multiply to 65. The numbers in the right column multiply to 54.

@mikejacobs.bsky.social Sep 14, 2026, 11:14 AM

Start your week with this #yohaku. Fill in cells with 9 different factors of 240 to get totals shown in each row/column. #mathsky #iTeachMath

Use 9 different factors of 240 in a 3 by 3 grid. The numbers in the top row add to 10. The numbers in the middle row add to 24. The numbers in the bottom row add to 72. The numbers in the left column add to 7. The numbers in the middle column add to 73. The numbers in the right column add to 26.